This invention relates to piezoelectric quartz vibrators provided thereon with electrodes for heating the quartz plates so as to effect compensation in the change in vibration frequency caused by surrounding temperatures.
Piezoelectric quartz vibrators provided with heating electrodes uniformly around the exciting electrodes have heretofore been known. In FIG. 1, such a quartz vibrator having excitation electrodes 1 and 2 and heating electrodes 4 of an open ring form disposed on and along the periphery of the vibrator body is shown. Such heating electrodes are controlled in temperature by themselves or by means of other control elements so that the vibrator body can be heated for keeping a stable frequency-temperature characteristic of said vibrator body.
Actually however, in such a quartz vibrator of prior art, compensation in the change of the resonant frequency caused by an interior strain of the vibrator body cannot be effected by means of the means for controlling temperature. Such an interior strain of the vibrator body caused by heat produced by heating electrodes 4 caused a change in the resonant frequency of said vibrator body.
Therefore, a quartz vibrator having a high stability could not be afforded by means of the foregoing prior art if said quartz vibrator of the foregoing prior art could have merits of small power consumption and a short starting period before reaching a stationary state.